Asiago spectroscopic and photometric observations of AT2016bau

ATel #8818; V. Granata (DFA, UniPd), S. Benetti, E. Cappellaro, N. Elias-Rosa, A. Pastorello, L. Tomasella (INAF OAPd), V. Nascimbeni (DFA UniPd), P. Ochner, L. Tartaglia, G. Terreran, M. Turatto (INAF OAPd)
on 15 Mar 2016; 09:18 UT
Credential Certification: Lina Tomasella (lina.tomasella@oapd.inaf.it)

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The Asiago Transient Classification Program (Tomasella et al. 2014, AN, 335, 841) reports the spectroscopic classification of AT2016bau, discovered by Ron Arbour in NGC 3631.

The observation was performed with the Asiago 1.82 m Copernico Telescope (+AFOSC; range 340-820 nm; resolution 1.4 nm).

 
Name                    | Discovery  UT | Obs. Date UT  |  z       | Type | Phase     | Notes 
AT2016bau               | 20160313.974  | 200160314.970 | 0.003856 | Ib   | young     | (1)  

(1) Adopting a redshift z=0.003856 (Tifft and Cocke 1988, ApJS, 67, via NED) for the host galaxy NGC 3631, a good match is found with SN 2004gq (Modjaz et al. 2014, AJ, 147, 99), 7-10 days before the maximum light. The early phase is supported by the high velocity expansion (about 16800 km/s) for the HeI 587.6 nm absorption.

Based on AFOSC multi-band imaging, we measured the following apparent AB magnitudes: u=18.87(0.03) mag, g=17.66(0.02) mag, r=17.50(0.03) mag, i=17.49(0.03) mag, z=17.59(0.02) mag. Given the galaxy distance modulus (30.41 mag via NED) the absolute magnitude turns out to be -12.9 mag in r-band, at the very faint end of the Ib luminosity function (Drout et al. 2011, ApJ, 741, 97) even considering the early phase.

Classification was done with GELATO (Harutyunyan et al. 2008, A&A, 488, 383) and SNID (Blondin and Tonry 2007, ApJ, 666, 1024). The Asiago classification spectra are posted at the website http://sngroup.oapd.inaf.it.

Padova-Asiago SN group